In 2012 police say they were made aware of 1023 cases of sexual offences on public transport which rose to more than 2000 2087 by 2015. During this period British Transport Police and TFL launched Project Guardian - a drive to encourage women who had been attacked to come forward.

Officers say it led to a 36 percent increase in arrests between 2014 and 2015 - and that this latest stage in their Report It Stop It Campaign aims to give victims confidence that they will be taken seriously, and that offenders will be caught.